In oil well operations where use is being made of radio frequency type down hole heating to free heavy petroleum products from certain formations, use has been made of ceramic tubing and the ends of such tubing section have are specially constructed in accordance with the description in the above mentioned copending application. In that type of tubing connectors, the connections of tubing sections are made by means of clamping the connectors together since the operations preclude applying torque for connecting or disconnecting tubing sections. In making up tubing strings using that type of tubing sections, a stabbing box structure has been developed in accordance with this invention. It permits the alignment of tubing sections and holds the connector ends of two tubing sections in place, ready for being clamped together as a string of tubing is made up. Such stabbing box also has the attribute of acting as a safety slip in case the slips holding a tubing string at the well head should let go, so that the tubing string would not be lost downhole.
In the past there have been suggestions of various structures for acting to prevent drill pipe or tubing strings from falling into the hole. However, none of the prior structures known to the applicant have provided any apparatus or structure which was like the applicants stabbing box and safety slip construction. Thus, there is a U.S. Pat. No. 2,575,831 to W. L. Pearce, Nov. 20, 1951 which shows a drill pipe support apparatus that is apparently particularly applicable to the withdrawal of drill pipe strings in an operation using a rotary drilling system. It is not concerned with any stabbing arrangement or operation in connection with making up tubing strings or the like.
There is also a U.S. Pat. No. 3,475,038 to L. Matherne, Oct. 28, 1969 which shows a so called "Pipe Stabber with Set Screws". However, the structure shown by that patent is for use with standard type tapered thread ends of drilling pipe or tubing. And, in addition it has the stabbing guide thereof attached by set screws on the upper end of a section of pipe being made up into a string thereof. Such arrangement and structure is clearly not applicable to the applicants invention. Also, as to any safety slip function, it would be quite impractical since the set screws would clearly not hold a string of pipe or tubing should the slips let go.
In addition, there is a U.S. Pat. No. 4,194,765 to Reddy, Mar. 25, 1980. However, that patent deals with a guide sleeve that helps line up and engage the ends of telescoping type tubing structure that slides longitudinally together in making connection of one tube to the next. It is not relevant to the type of tubing and connectors which are to be joined in accordance with the applicants invention.